User interfaces have traditionally relied on input devices such as keyboards, which require physical manipulation by a user. For instance, traditional human-to-computer interfaces are based on some form of physical touch, such as depressing keys on a computer keyboard, moving a mouse and clicking a button, moving a joystick, tapping a touch screen, and so forth. This physical type of human-to-computer interface is reliable and precise.
Increasingly, however, it is desired to detect and monitor the physical positions and movements of users within a scene or environment. User motions and gestures can be used in some environments as user commands and inputs to automated systems. In particular, it may be desirable to provide input from a user to a computerized system without contacting a surface or using an input device coupled to the computerized system.
Accordingly, there is a need to develop and improve ways to detect input provided by a user that does not rely on touching a surface or using an input device coupled to a system.